TRS:
 {    minus(x, 0()) -> x,
  minus(s(x), s(y)) -> minus(x, y),
        double(0()) -> 0(),
       double(s(x)) -> s(s(double(x))),
       plus(0(), y) -> y,
      plus(s(x), y) -> s(plus(x, y)),
      plus(s(x), y) -> plus(x, s(y)),
      plus(s(x), y) -> s(plus(minus(x, y), double(y)))}
 Fail